Free bone segments require both stability and appropriate apposition of the segments as well as good blood supply to heal. Due to the high energy typically involved in bone fractures, highly fragmented fractures are commonly encountered. This amalgam of traumatized soft tissue and complex fracture morphology is effectively non-reconstructable within a reasonable timeframe typically associated with surgery. Further, the additional trauma to the blood supply and soft tissues incurred during an open surgical approach is detrimental to the local healing environment. This can result in malunions, non-unions, delayed healing, infections and suboptimal outcomes. In short, open surgical approaches are often not desirable. However, diaphyseal fractures frequently require some form of surgical intervention and fractures involving a joint surface must be restored anatomically. The surgical intervention will generally involve reduction of the bone segments, which involves translating them into alignment. The reduction can be either open or closed. In open reduction, the fracture segments are exposed surgically by dissecting the surrounding tissues. In closed reduction, the manipulation of the bone segments is conducted in a minimally invasive manner and without full surgical exposure.
One surgical approach to bone reduction and stabilization is open reduction with internal fixation (ORIF). ORIF requires an open surgical approach to the fracture for anatomic reduction and rigid stabilization of all major fracture fragments. The size of the required incision in ORIF procedures can be large. This open approach damages the local blood supply along with the fracture hematoma and its beneficial cytokines. As a result, investigation into less invasive techniques that promote the use of the bodies' innate biological healing mechanisms and minimize disturbances to the local fracture biology have been gaining support.
Another surgical approach to bone reduction and stabilization is minimally invasive osteosynthesis (MIO). MIO places emphasis on preservation of the fracture biology, striving to maintain the local blood supply and fracture hematoma with its beneficial cytokines while restoring the bone to pre-fracture length and alignment. The applied minimally invasive definitive fixation then provides sufficient mechanical stability such that secondary bone healing via callus formation and osseous remodeling occurs, although primary bone healing without callus formation may still be achieved with more simple fracture configurations. Benefits of the MIO approach includes reduced risk of post-operative infection, preservation of osteogenic potential and blood supply and faster healing.
Current techniques for MIO consist of external skeletal fixation (ESF), a hybrid open-but-do-not-touch (OBDNT) technique where the fracture site is opened but minimally disturbed, minimally invasive plate osteosynthesis (MIPO) and interlocking nail application. In all techniques where the fracture site is not exposed, the fracture site is manipulated via remote incisions, and reduction and definitive stabilization are assessed using intraoperative fluoroscopy during active surgical reduction. These techniques require intraoperative radiation exposure to operating room personnel and the patient and are expensive.